Power from the people
New net-metering law clears the way for home-based electricity generation

by
Bob McEowen

Catharine Mouton and Steven Segal can generate 4,200 watts of electricity from photovoltaic cells installed on the roof of their home. Under a new net-metering law, the couple sells excess power back to their electric co-op.

A new power producer is delivering energy to Missouri’s electric cooperatives. No, it’s not a coal-fired plant, nor is it the utility-scale wind farms in northwest Missouri. The new source of energy is a small wind turbine owned by Derek Fox and his wife, Stephanie Essman.

“When we built the home, we really wanted to try to be as environmentally conscious as possible. One of the things we did was put up a wind generator,” says Fox, whose timber-frame home west of Columbia also features hyper-efficient structural insulation panels and passive solar heating.
“We knew it would take a very long time for it to pay for itself, but it was something we thought was the right thing to do and, hopefully, would inspire others to at least consider alternative energy sources.”

Fox and Essman, both assistant professors at the University of Missouri College of Veterinary Medicine, are one of three providers of “distributed generation” served by Boone Electric Cooperative. Whenever their turbine produces more electricity than the couple is consuming, the excess power flows onto the co-op’s lines and supplies energy to their neighbors.

A new law, which took effect Jan. 1, requires utilities to cooperate with home-based power producers and buy their surplus energy. Under terms of Missouri’s “Net-metering and Easy Connect Act,” the full retail value of the electricity the couple sells to the co-op is deducted from their monthly bill.

“At the end of the month, when we settle the bill, we look to see how much they put on the grid and how much they bought from us,” says Chris Rohlfing, Boone’s manager of member services. “If they bought 1,000 kilowatt-hours (kwh) from us, and they put 100 back on the grid, they would pay for the net difference. They would pay for 900.”

If ever they produce more energy than their total monthly consumption, they will receive a credit for the “avoided cost” of generating that electricity — about 3 or 4 cents per kilowatt-hour most months, as opposed to Boone’s approximate 8-cent retail rate.

The new law applies to generation devices with up to 100-kilowatt (kw) capacity and is in effect until home generation accounts for 5 percent of total system capacity. All Missouri utilities must have net-metering policies in place by October.

Currently, 12 Missouri electric co-op members are connected to the grid under the terms of the law. In total, these picayune power producers account for less than 100 kw of generation capacity — an infinitesimal contribution to the 3,500-megawatt peak demand of the state’s electric cooperatives.

The Skystream 3.7 turbine Fox and Essman installed is advertised as producing 1.9 kw of continuous output. With variable winds, turbines rarely produce their rated capacity. But, in theory, the unit could make enough electricity to power a few dozen compact fluorescent light bulbs and some small appliances — or a single energy hog such as a toaster oven or a hand-held hair dryer.

Since it was installed in February, the turbine — which cost about $10,000 to purchase and install — has generated 424 kwh of electricity, worth about $35 at today’s prices. The couple consumed nearly all of that power, selling just 13 kwh, or about a dollar’s worth of electricity, to the co-op. “It’s a very nominal amount,” Fox admits.

By comparison, Steven Segal and his wife, Catharine Mouton, are mega-producers. The couple installed photovoltaic solar panels capable of producing 4.2 kw of electricity on the roof of their home west of Columbia.

“If there’s a lot of sun and you’re doing everything right, it can meet almost all of our energy needs in months requiring little energy for heating or cooling,” says Segal, a professor at MU’s Department of Medical Pharmacology and Physiology. “We had almost no electric bill one month. Every month we sell (the co-op) something.”

Since installing their $50,000 solar array in April 2007, Segal and Mouton have produced about 7,200 kwh — or slightly less than $600 worth of electricity. Nearly 2,000 kwh of that energy flowed onto the grid.

Home-based power producers must notify their utility of the exact brand and model of equipment they will be using, and provide a site-specific wiring diagram. They must also sign a net-metering agreement with Associated Electric, which supplies power to Missouri’s electric co-ops.

Any devices hooked up to the grid must comply with the National Electrical Code and all industry standards for distributed generation equipment. These standards spell out how power inverters interface with utilities. In addition to converting DC power to 60-cycle AC, the inverter shuts down power if there is an outage on the utility’s lines. While this prevents using wind or solar as back-up power, it ensures that utility workers will not be harmed by the unexpected flow of electricity. Under the new law, a co-op may disconnect any member whose power inverter does not comply with the standards.

The new law removes a requirement that home power producers carry liability insurance, but specifies that the manufacturers of distributed generation devices are responsible for any accidents or damage caused by their equipment. Power producers must also purchase two-way meters to keep track of electricity consumed and produced. The meters, which cost as much as $500, are just part of what proves to be a very expensive means of generating electricity.

Return on investment was not the overriding consideration when the couple decided to incorporate solar power into their new home plans. Segal and Mouton’s home was built with a southwest exposure to take advantage of passive solar warming in the winter, while large overhanging eaves block the sun’s rays in summer. In addition to the photovoltaic cells, the house also incorporates a separate solar system to provide radiant floor heating and hot water.

“It just sounded like a cool thing to do. Let’s use solar energy,” Segal says. “That’s what we ought to be doing — turning photons into heating, and toasting our bread and cooking our food. It’s a matter of can we generate energy with a minimum impact on the environment.”

Rohlfing says Segal’s attitude is typical of others who make the investment to generate their own electricity. It takes a commitment to the environment before a homeowner will fund a home generation system that costs $10,000 or more. Co-op members in search of lower electric bills soon learn that other technologies — such as compact fluorescent lighting, upgraded insulation, Energy Star appliances and high-efficiency heating and cooling systems — offer much more immediate savings.

“These folks are pioneers,” Rohlfing says. “They invested their money in developing technology, knowing they were early in the game and that there was a good chance they would never see a return on their investment.”

Rohlfing says he fields five or six calls every week from members inquiring about installing wind or solar power at their homes. Most are turned off by the cost, but a few will proceed, motivated by the desire to participate in a rapidly advancing renewable energy movement.

“There’s only three of us in all of Boone County that have any kind of alternative energy that is feeding back into the grid, but that’s three that weren’t there before,” says Fox.
“If more and more people can be involved with some of this, especially more people in rural locations that can use solar panels or wind energy, or just use less, it all adds up,” he says. “It makes a difference.”

For more information about net metering, contact your local electric cooperative, or visit the Missouri Department of Natural Resources Energy Center’s Web site at www.dnr.mo.gov/energy.